Improvement in carriage-jacks



.l'o all whom it may concern ttttted -i ABNER n.. eILnaor ADAMspNE-W- Yoan.

IMPROVEMENT 1NV CARRIAGE-Jacks.

The Schedule'refened to in these`Letters Patent and vmaking part of the same.

Be it known um I, ABNER n. ems, 0f Adams,

`in the countyot'Jeerson-and State of New York,

have `invented anew and valuable Improvement in lagon-Jacks; and I do'hereby declare that Athe following is a full', clear,'and exact description ot' the con-` struction. and .operation of thc same, reference heilig f had tothe, annexed drawing making a part of this specification, and `to the letters and figures of reference marked thereon.

Figure 1, of the drawing, isa perspective riew of my invention. e e l Figure 2 is a. vertical sectionof the some.

Figure 3 is a detailed sectional View.

My invention relates to that class of lifting-jacks which areccnstructed ofl two-parallel bars of unequal length, united together by a tongue-and-groove joint;

and

It consists in constructing andarraugingsuch tongueand-groove joint in suoli manner that,'\vhen the unhoged end of said shorter bar is brought to an angle of about ten degreesfrom a. right angle with the longer bar, its hinged end becomes rigidly fixed by shoulders, so `constructed and arranged as to prevent said bars, respectively, from approaching morenearly to a right angle than the ten degrees mentioned, thereby giving great strength and iirmnessto the said uniting joint.

A, of the drawing,:represents the longer of two bars that constitute 'rn y liftirng-jack,` and B, the shorter bar thereof.-

C, to enable the operator to apply it to a load nearer the ground' tha'nwould be possible if the end ofsaid groove, and also through the tongue holding said parts firmly together. v

The tongue I) is lconstructed in a circular form, as shown ouiig. 2, and that portion oi' bar A adjoining and immediately below said tongue is` also made circular, as shown at a ou Iigs.- l and 2, thereby forming a shoulder on said bar, as represented at n.

On the bar B I form the lips of the hinge iu a circular form, as the drawing represents, and I cut a shoulder therein, as shown at y, which, when on duty, fits closely upon the shoulder n ofthe longer bar, iu the manner'represented on fig. 1, and prevents said barfrom reaching' a point more nearly a right angle than about t'en degrees.. l Y

The above-described arrangement of constructing shoulder n upon the bar A, and shoulder y upon the,

bar B, securesgreat strength and firmness to the joint, and serves to relieve' the connecting-pin from unnecessary strain.

Ialso consider-'my method ot'constructing the tongue d D in such manner that its upper side or edge shallnot Y bars A and B, the haltlrulejoint, constructed ol tongue i 'Ihis bar B isv formed w' h a set-cti' o1" shoulder at D on the bar A, and corresponding lips on barB, united by pin o, and so arranged 'that the shoulders n and y shall operate together, substantially as specified.

In testimony that I claim the above, I have hereunto subscribed my name in the presence. of two wit- 

